I'm not really an expert on PHP coding but is it possible to do like a fade effect on a certain graphic? Like I'm trying to achieve an effect by where a mouse goes on some graphics and then it fades to reveal another type of graphics. I want this to also look like a smooth transition and when the mouse is removed from that revealed graphics, it returns to the original one that was covering it. Any help or does this require Javascript?

That requires Javascript as far as I'm aware. I'll try find a guide on it though as I've seen one before which may help.

EDIT: http://slayeroffice.com/code/imageCrossFade/xfade2.html

I recommend a javascript library like jQuery or Scriptaculous (think that's the name). They have this ability built in, in ready-to-use functions.